编辑代码

public class Str3{
	public static void main(String args[]){
		String str1 = "good"; 
		String str2 = "morning";
		System.out.println(str1 +" "+str2);
		String str3= "how ";
		String str4= "are you";
		System.out.println(str3.concat(str4));
	}
}